Fibers made from acrylonitrile polymers and bentonite



FIBERS MADE FROM ACRYLONITRILE POLYMERS AND BENTONITE John R. Caldwell, Kingsport, Tenn., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application April 7, 1954, Serial N 0. 421,684

3 Claims. (Cl. 260-41) This invention relates to the preparation of acrylonitrile polymer fibers having improved dyeing properties and to the solutions from which such fibers may be formed. More particularly it is concerned with the manufacture of acrylonitrile polymer fibers that contain substantial quantities of bentonite in a highly dispersed form which permits the dyeing of the fibers by many common dyes and dyeing methods.

It is well known that acrylonitrile polymers and copolymers have been found difficult to dye since they are quite insoluble, unreactive and hydrophobic. Therefore, methods for dyeing such polymers are in depend and have considerable interest especially in the textile field.

An object of the invention is to furnish a method for preparing acrylonitrile polymers containing bentonite in a highly dispersed state. Another object of the invention is to prepare and to provide compositions containing acrylonitrile polymers and bentonite that can be filtered and spun by the usual methods. Another object of the invention is to provide acrylonitrile polymer fibers that show excellent afinity for several classes of dyes. A further object of the invention is to provide acrylonitrile fibers that have an improved ironing or sticking temperature. Other objects will appear hereinafter.

In accordance with the present invention these and other objects are attained by polymerizing acrylonitrile in the presence of an aqueous dispersion of bentonite. Other vinyl monomers may also be present, along with acrylonitrile to give interpolymers. Fibers made according to the process of this invention dye well with cellulose acetate dyes, acid wool dyes, vat dyes, and some direct cotton dyes. The fibers dye especially well with acid wool dyes to give deep shades that are fast to washmg.

It is well known that, in general, fibers containing more than about 90% acrylonitrile have little or no aflinity for the common classes of dyes when applied by the ordinary methods. Hence, it is very surprising to find that such fibers, when containing bentonite, can be dyed to heavy shades with most dyes.

It is also surprising to find that the presence of bentonite raises the ironing temperature or hot-bar sticking temperatures of the fibers by as much as 20 to 40* C. This is an important factor when acrylonitrile interpolymers are employed. It is well known that most interpolymers containing less than about 85-90% acrylonitrile stick to the hot bar below 200 C. By incorporating bentonite in such fibers, the sticking temperature is raised to 220-240 C. thus greatly increasing their utility.

Bentonite is a colloidal clay that readily solvates in water and disperses to a particle size less than 1 micron. It does not solvate and disperse in organic solvents such as dimethylformamide, gamma-butyrolactone, ethylene carbonate, etc. Hence it cannot be mixed with acrylonitn'le polymer solutions in such solvents. However, under the condiitons employed in the process of this invention, an intimate mixture or complex is formed between the acrylonitrile polymer and the bentonite. This complex dissolves readily in spinning solvents to give a bentonite dispersion that passes through filters, spinnerettes, etc., in a normal manner.

From 10 to 25% and preferably 10% to 15% ben-- tonite is used, based on the weight of monomers.

Acrylonitrile or mixtures of acrylonitrile with other monomers are employed. The interpolymers contain at least and preferably to acrylonitrile. Suitable modifying monomers inclde methyl acrylate, methyl methacrylate, vinyl acetate, vinyl chloride, isopropenyl acetate, methacrylonitrile, methallyl alcohol allyl acetate, etc. A particularly valuable class of modifying monomers are derived from unsaturated amides such as acrylamide, methacrylamide, N-methyl acrylamide, N- ethyl methacrylamide, N-isopropyl acrylamide, etc.

Peroxide catalysts such as sodium or potassium persulfate, hydrogen peroxide, perborates, etc., are used. From 0.1% to 3.0% and preferably 0.5% to 1.0% cat- -alyst is used, based on the weight of monomers.

Surface active agents such as fatty alcohol sulfates, aromatic sulfonates, fatty acid soaps, and fatty acid amide sulfates may be employed. Nonionic dispersing agents such as ethylene oxide-phenol condensation products, polyethylene oxide or polypropylene oxide condensation products, etc., are useful. Quaternary ammonium compounds such as lauryl pyridinium chloride or octadecyl trimethyl ammonium chloride can be used.

The reaction may be carried out in the presence of activators and molecular Weight regulators such as sodium bisulfite, dodecyl mercaptan, t-amyl mercaptan, etc.

A temperature of 30 to C and preferably 45 to 70 C. is used. The reaction time is 2 to 24 hours.

The products are soluble in the solvents commonly used for polymers containing 85% or more acrylonitrile. Suitable examples include dimethylformamide, dimethyl acetamide, gamma-butyrolactone, ethylene carbonate, ethylene cyanohydrin and succinodinitrile.

Filaments may be spun from my spinning solutions by suitable well known wet or dry spinning processes. The wet and dry spinning processes described in the copending E. V. Martin application S. N. 159,089, filed in the United States on April 29, 1950, and entitled Improvement In Spinning Acrylonitrile, now Patent 2,697,023 of December 14, 1954, may be employed.

The present invention is further illustrated in the following examples.

Example 1 Three grams of bentonite is stirred with 200 cc. water to give a fine dispersion. The folowing materials are then added:

Grams Acrylonitrile 25.0 Sodium dodecyl sulfonate 0.7 Potassium persulfate 0.3 Dodecyl mercaptan 0.2 Phosphoric acid 0.5

The mixture is agitated at 50 C. for 18 hours. The polymer separates as a granular powder that is filtered, washed; and dried. A yield of 26 g. is obtained.

The product is dissolved in 'g. of dimethylformamide to give a smooth, translucent dope that filters well, with no loss of bentonite on the filter. The dope is spun by the dry or evaporative method to give fibers having a tensile'strength of 2.5 to 3.0 grams per denier and elongation of 16 to 22%. The fibers dye well with cellulose acetate dyes, acid wool dyes, soluble vat dyes, insoluble vat dyes, and the direct cotton dyes mentioned hereafter. The acid wool dyes are especially fast to laundering.

The fibers show a hot bar sticking temperature of 230- 240 C.

Patented Oct. 1, 1957 Example 2 Six grams of bentonite is stirred with 200 cc. water to give a fine dispersion. The following materials are then added:

. Grams Acrylonitrile 25.0 Sodium dodecyl sulfate 0.7 Potassium persulfate 0.3 Dodecyl mercaptan 0.2 Phosphoric acid 0.5

The mixture is agitated at 50 C. for 18 hours. The polymer separates as a granular powder that is filtered, washed, and dried. A yield of 26 g. is obtained.

The product is dissolved in 120 g. of dimethylformamide to give a smooth, translucent dope that filters well, with no loss of bentonite on the filter. The dope is spun by the dry or evaporative method to give fibers having a tensile strength of 2.5 to 3.0 grams per denier and elongation of 16 to 22%. The fibers dye well with cellulose acetate dyes, acid Wool dyes, soluble vat dyes,

insoluble vat dyes, and the direct cotton dyes mentioned hereafter. The acid wool dyes are especially fast to laundering.

The fibers show a hot bar sticking temperature of Example 3 Three grams of bentonite is dispersed in 400 cc. water and the following materials are added:

The mixture is stirred at 5560 C. for 8 hours. The precipitated polymer is filtered, Washed, and dried to give a yield of 42 g. product.

The product dissolves in dimethylformamide, gammabutyrolactone, ethylene carbonate, and ethylene cyanohydrin to give smooth, translucent solutions that filter well.

Ten grams of the product is dissolved in 55 g. of dimethylformamide and the solution is extruded through a multi-hole spinnerette into a coagulating bath of 75 waterdimethylformamide. The fibers are washed and drafted 600% to give a tensile strength of 2.8-3.2 grams per denier and elongation of 20-25%. The fibers show excellent aifinity for cellulose acetate dyes, acid wool dyes, vat dyes, and direct cotton dyes.

The fibers have a hot bar sticking temperature of 220-230" C. This copolymer, containing 10% N-isopropyl acrylamide, normally gives fibers that stick to the bar at about 200 C. The presence of the bentonite raises this value by 20-30 C.

The composition may be dry spun from solvents such as dimethylformamide, dimethyl acetamide, and gammabutyrolactone.

Example 4 Three grams of bentonite is dispersed in 400 cc. water and the following materials are added:

The mixture is stirred at 55-60 C. for 8 hours. The

precipitated polymer is filtered, washed, and dried to give a yield of 42 g. product.

The product dissolves in dimethylformarnide, gammabutyrolactone, ethylene carbonate, and ethylene cyanohydrin to give smooth, translucent solutions that filter well.

Ten grams of the product is dissolved in 55 g. of dimethylformamide and the solution is extruded through a multi-hole spinnerette into a coagulating bath of water-25 dirnethylformamide. The fibers are washed and drafted 600% to give a tensile strength of 2.8-3.2 grams per denier and elongation of 20-25%. The fibers show excellent afiinity for cellulose acetate dyes, acid wool dyes, vat dyes, and direct cotton dyes.

The fibers have a hot bar sticking temperature of 220-230 C. This copolymer, containing 10% N-isopropyl acrylamide, normally gives fibers that stick to the bar at about 200 C. The presence of the bentonite raises this value by 2030 C.

The composition may be dry spun from solvents such as dimethylformamide, dimethyl acetamide, and gammabutyrolactone.

Example 5 Three grams bentonite is dispersed in 250 cc. water and the following materials are added:

Grams Acrylonitrile 27.0 Isopropenyl acetate 3.0 Potassium persulfate 0.3 Dodecyl mercaptan 0.2 Sodium bicarbonate 2.0

The mixture is stirred at 50-55 C. for 6 hours. The product is filtered, washed, and dried. The yield is 25-28 g.

The product gives smooth dopes in the solvents listed above. The fibers stick to the hot bar at 215-225 C. They dye well with cellulose acetate dyes, acid wool dyes, vat dyes and the direct cotton dyes mentioned hereinafter.

Example 6 Three grams bentonite is dispersed in 250 cc. water and the following materials are added:

Grams Acrylonitrile 27.0 Vinyl acetate 3.0 Potassium persulfate 0.3 Dodecyl mercaptan 0.2 Sodium bicarbonate 2.0

Cellulose acetate dyes:

Eastman Blue BGF Eastman Blue BNN Eastman Fast Violet SRLF Eastman Fast Yellow GLF Eastone Scarlet BG Eastone Orange 3R Acid wool dyes: Color Index Number Xylene Milling Black B 304 Vat dyes:

Ponsol Jade Green 1101 Ponsol Navy Blue RA 1101 Ponsol Red BND 1162 Ponsol Violet RRD 1104 Ponsol Yellow 3R 452 Sulfanthrene Brown GR 121 Mordant dyes:

Omega Chrome Brown 2R 98 Omega Chrome Dark Violet D 169 Omega Chrome Orange G 274 Omega Chrome Red B 652 Omega Chrome Yellow 3G 52 Omega Chrome Black P 204 These cellulose acetate dyes, wool dyes, vat dyes, and mordant dyes may be applied to the fibers by the method shown in Diserens, Louis, Chemistry and Technology of Dyeing and Printing, New York, The Reinhold Corporation, vol. I (1948), vol. II (1951), translated from the second German edition.

I claim:

1. Fibers having improved dyeing qualities with dyes selected from the group consisting of cellulose acetate dyes, acid wool dyes, vat dyes and mordant dyes, and im proved sticking temperature made from acrylonitrile polymer compositions containing at least 80% of acrylonitrile in the polymer and containing in the composition, 10 to 25% of finely divided bentonite having a particle size less than 1 micron.

2. Fibers having improved dyeing qualities with dyes selected from the group consisting of cellulose acetate dyes, acid wool dyes, vat dyes and mordant dyes, and improved sticking temperatures made from polyacrylonitrile containing 10 to 25% of finely divided bentonite having a particle size less than 1 micron.

3. Fibers having improved dyeing qualities with dyes selected from the group consisting of cellulose acetate dyes, acid wool dyes, vat dyes and mordant dyes, and improved sticking temperatures, made from an acrylonitrile interpolymer containing to acrylonitrile and a comonomer selected from the group consisting of N-methyl acrylamide, N-ethyl methacrylamide, isopropyl acrylamide, isopropenyl acetate and vinyl acetate and containing 10 to 25% by weight of finely divided bentonite having a particle size less than 1 micron.

References Cited in the file of this patent UNITED STATES PATENTS 2,579,008 Naps et al. Dec. 18, 1951 FOREIGN PATENTS 594,653 Great Britain Nov. 17, 1943 675,627 Great Britain July 16, 1952 

1. FIBERS HAVING IMPROVED DYEING QUALITIES WITH DYES SELECTED FROM THE GROUP CONSISTING OF CELLULOSE ACETATE DYES, ACID WOOL DYES, VAT DYES AND MORDANT DYES, AND IMPROVE STICKING TEMPERATURE MADE FROM ACRYLONITRILE POLYMER COMPOSITONS CONTAINING AT LEAST 80% OF ACRYLONITRILE IN THE POLYMER AND CONTAINING IN THE COMPOSITION, 10 TO 25% OF FINELY DIVIDED BENTONITED HAVING A A PARTICLE SIZE LESS THAN 1 MICRON. 